What is “frozen_string_literal” in Ruby?

In order to have a transition path to this coming big change, it was decided to have a magic comment at the beginning of files, so you can use in Ruby 2.x.
To do so, just add this comment in the first line of your files:

# frozen_string_literal: trueclassYourClass# ...end

Try adding it to your spec_helper or rails_helper file and let me know in the comments if your performance gets any better.